nav.css

* {
    margin: 0;
    padding: 0;
}

nav {
    background-color: yellow;
    border: 20px;
}

ul {
    display: flex;
    list-style: none;
    font-size: xx-large;
}

li{
    padding: 20px;
    transition-duration: 2s;
}

li:hover{
background-color: green;
transition-duration: 1.7s;
}

a{
    text-decoration: none;
}